Hakim Omar Khayyam (427-510 A.H.) was the Iranian philosopher, mathematician, astrologer and ruba'i writer of Seljuk Era. His fame is mainly due to his writings of ruba'i, which are of global fame and they are translated into most live languages of the world. Among his major achievements is developing Jalali Calendar that was conducted during the reign of Malik Shah Seljuq and at the ministration time of Nezam ul-Mulk. Hakim Omar Khayyam had mastered mathematics, astrology, as well as literary, religious and historic sciences. Tomb of Hakim Omar Khayyam is located in the garden of Imamzadeh Mahruq in Nishapur. The garden of Imamzadeh Mahruq is a beautiful garden with a library, museum, and inn. The statue of Hakim Omar Khayyam is installed at the courtyard entry of this garden. The building of this tomb of is among the prominent constructions designed in Iran that expresses a successful integration of traditional and modern elements. In the inscriptions of this building, twenty ruba'is of Hakim Omar Khayyam are transcribed in Nasta'ligh. Tomb of Hakim Omar Khayyam has been registered as a national monument of Iran.